Reports until 11:14, Wednesday 13 April 2022
H1 TCS (ISC)
jenne.driggers@LIGO.ORG - posted 11:14, Wednesday 13 April 2022 - last comment - 16:06, Wednesday 13 April 2022(62598)
2 point absorbers on ITMX?

While Camilla and Georgia work to complete the full analysis of HWS data, I took a sneak peak at some times from Tuesday morning, while cooling down from a ~15 hour 50W lock. 

The reference times are about a minute after we lost lock (note to self: Camilla pointed out that the HWS data is much more clean if you use as a reference a time without the main beam).  I have 2 sets of images, one set for 2 min after the reference, and one set for ~40 mins after the reference.  Each set has an ITMX and an ITMY image.

In the 40 min later images, it looks like the cooldown amount of both ITMX and ITMY are quite similar.  I naiively take this to mean that their bulk absorptions are roughly similar.  (Recall that the apparent size of the ITMs is different on their HWSs).

However, in the 2 min images, it looks quite clear that we have 2 point absorbers on ITMX.  :(  Team TCS will have to help us understand how these relate to our past point absorbers.

I'm not totally sure what we should do with this info, other than perhaps we should try again moving spots on the ITMs.  I propose switching control over to ITMX spot (and have ITMY spot be the free one that just follows along), watching live HWS data to see that we move away from the spot, and then see if we can move ETM spots to keep arm powers high.

 

Images attached to this report
Comments related to this report
camilla.compton@LIGO.ORG - 13:34, Wednesday 13 April 2022 (62599)

You could see at hint of these in the power up data alog 62566 too.

jenne.driggers@LIGO.ORG - 15:51, Wednesday 13 April 2022 (62604)

After having move the spots to get better arm powers and recycling gain, and after a lockloss from there, here is another ~2 min cooldown plot of ITMX.  I seem to have succeeded in moving the spot somewhat to the left, but may be actually illuminating the point absorbers more.  Or, it could be that this is just after we had increased the circulating powers, and that's why it looks like they're more illuminated?

Images attached to this comment
aidan.brooks@LIGO.ORG - 16:06, Wednesday 13 April 2022 (62605)

Looks like there is a 3rd point absorber there ...

 

Images attached to this comment